lan

import javax.xml.bind.DatatypeConverter;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.InetAddress;
import java.net.MulticastSocket;
import java.net.NetworkInterface;

public class Companytec {

  public static void main(String[] args) throws IOException {
    //Address
    String    multiCastAddress = "255.255.255.255";
    final int multiCastPort    = 30718;
    final int bufferSize       = 1024 * 4;

    //Create Socket
    InetAddress     group = InetAddress.getByName(multiCastAddress);
    MulticastSocket s     = new MulticastSocket(28675);

    s.setNetworkInterface(NetworkInterface.getByName("en0"));
    //    s.joinGroup(group);

    byte[] data = DatatypeConverter.parseBase64Binary("AAEA9g==");

    //Send data
    s.send(new DatagramPacket(data, data.length, group, multiCastPort));

    //    while (true) {
    //Create buffer
    byte[]         buffer = new byte[bufferSize];
    DatagramPacket dgram  = new DatagramPacket(buffer, bufferSize, group, multiCastPort);
    s.receive(dgram);

    String inetaddress = (dgram.getAddress()).getHostAddress();

    String msg = new String(buffer);
    //    System.out.println(msg);
    //    System.out.println(inetaddress);
    if (msg.indexOf("X90") > 0) {
      System.out.println(inetaddress);
      //      break;
    }
  }


}